


Undertale  X READER oneshots lemon

by Ravenwritesthings



Category: Undertale (Video Game)
Genre: Alternate Universe - Flowerfell (Undertale), Alternate Universe - Mobtale (Undertale), Alternate Universe - Sciencetale (Undertale), Alternate Universe - Underswap (Undertale), Bara Sans (Undertale), Dom Sans (Undertale), Rape/Non-con Elements, Smut, Underfell Mettaton (Undertale), Underfell Papyrus (Undertale), Underfell Sans (Undertale), Underswap Papyrus (Undertale), Underswap Sans (Undertale), Violence
Language: English
Status: In-Progress
Published: 2021-02-07
Updated: 2021-02-20
Packaged: 2021-03-13 02:34:58
Rating: Explicit
Warnings: Graphic Depictions Of Violence, Rape/Non-Con, Underage
Chapters: 4
Words: 3,532
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29271090
Author URL: https://archiveofourown.org/users/Ravenwritesthings/pseuds/Ravenwritesthings
Summary: Undertale one shots smut (I take request)
Relationships: Asgore Dreemurr & Reader, Asgore Dreemurr/Reader, Asgore Dreemurr/Toriel, Chara (Undertale) & Reader, Grillby (Undertale)/Reader, Mettaton & Papyrus (Undertale), Mettaton (Undertale)/Reader, Papyrus (Undertale)/Reader, Sans & Toriel (Undertale), Sans (Undertale)/Reader, W. D. Gaster/Reader
Comments: 13
Kudos: 26





	1. Oneshots I plan to do

So im gonna do undertale x reader one shots lemons (I decided to make a separate book with just fluff and no smut) , i take request but these are the ones I am planning to do 

Underfell sans x reader

Bara sans x reader

Gastor x reader 

Asgore x reader 

Underfell papyrus x reader 

Swap papyrus x reader

Mobtale sans x reader 

Original sans x reader 

Science sans x reader 

Underfell mettaton x reader

Reader is gender neutral with a vagina

Also I'm looking for co writers!


	2. Original sans x reader 🍋

It was almost midnight , papyrus had left to go spend the night at undynes ,leaving you and sans alone and you both decided to stay up late and watch scary movies 

you had known sans for a long time ,since you first fell into underground almost 3 years ago , and you started to develop feelings for the pun loving skeleton,  
but knowing sans would most likely never return your feelings  
you began pushed those feelings deep inside and tried to ignore them, which was proving to be very difficult

Every time he talked your face flushed and everytime he touched you your heart pounded it was almost impossible to ignore your feelings for him,but you loved hanging out with sans you didn't want to ignore him outright so you agreed to hang out with him tonight to watch movies

Sans didn't seem to notice that he was sitting painfully closely to you, both your legs and arms touched beside each other ,you wore your usual night time attire, shorts and a tee  
You were watching a horror movie, it wasn't your favorite type of movie but sans wanted to watch it so you agreed, your eyes where glued to the screen as you saw a little girl get her head chopped clean off causing you to wince , sans seemed to notice 

"You okay kiddo? I can turn this off if it's too scary for ya"

You shook your head 

"No im good!" You lied "let's just keep watching" you smiled nervously and turned back to the tv 

And then a jump scare happened 

You let out a small scream and hid in sans's chest 

You heard a small chuckle and you looked at sans, pouting 

"Hey don't laugh at me"

"Sorry kiddo, you're just so adorable" 

You blushed  
You then realize that your clinging onto sans, and quickly let go 

"Sorry i didn't mean to grab you like that haha.." You laugh nervously

He smiles and puts his arms up on the couch one around your shoulder 

You probably looked like a tomato 

"It's okay kid I don't mind, are you sure you're alright ? Your face looks all red"

You couldn't look sans in the eyes 

"Yeah im okay....i think I might be coming down with a human sickness" you lied again 

"Oh yeah, i think I read about that .... Your body heats up right?"

You nodded and sans raised a honey hand and placed it on your forehead 

You felt like you where on fire And felt heat pooling in between your legs 

He laughed 

"You know kid, you're a terrible liar"

"Wha-"

Sans pushed you onto the couch , and he leaned above you

"Don't play dumb, I can tell the difference between sick, and turned on" 

"I don't know what your talking abou-"

"I'm not a idiot,I see how you act around me, I can smell the arousal on ya..." He gripped your legs

Fuck, he noticed the whole time? And never said anything?!

Sans Leaned down and kissed you , it was odd but it felt nice and sensual  
Then you felt something wet and slimy touch your mouth 

You opened your eyes and saw a bright blue glowing

Oh my god, did sans have a tongue?!

You opened your mouth and sans slid his tongue inside 

You moaned as sans did that and that seemed to make sans go crazy 

you saw your clothes light up in sans blue magic and felt it tugging off your body, you sat up a little to make it easier soon he had all your pajamas off and you where completely naked in front of him 

Sans opened your legs and licked your stomach, all the way down to your already wet pussy  
And moved his tongue all the way around eventually finding the clit and making circles around it, you were a moaning mess, legs shaking 

"Look at me doll I wanna see your face when i make ya cum"

You opened your teary eyes to look at him as he ate out your pussy

Then sans hit the spot that made you see stars , you moaned sans's name and arched your back as you came all over sans's tongue 

You sat there for a minute just breathing heavily 

" Oh my god... That was amazing, I've never orgasmed before...." 

Sans laughed "you've never had a orgasm before? Must've slept with pretty lousy dudes"

You shook your head "nope, never slept with any one before" 

Sans eyes widened then he smiled " Shit really?, guess I'll have to be extra gentle " 

You gave him a confused look before sans pulled out a much erect blue dick out of his shorts 

"What?! How do you have a dick, ? You're a skeleton!" 

"I got a tongue dont i? It's magic kid"

Fair enough

"B-but that's huge!"

It was, it stood at almost 9 inches

Sans's grinned again 

" Don't worry, like i said I'll be real gentle, i got you kid" 

"Can you please not call me kid when your about to fuck me?"

Sans chuckled 

"Noted"

He shoved the tip in and it stung a little but after a moment you got used to it, and bucked your hips to shove more in, a little to much and it burned badly 

"Be careful , this is your first time you don't wanna force it" 

he held onto your hips and you both waited for the pain to fade away

And it soon did, you told sans he could move and he did slowly pushing it in and out , you moaned 

"Fuck...sans go harder please"

"You sure? I don't wanna hurt you...." 

You nodded "please sans , just go faster"

"Heh, how could I say no to that" 

He roughly thrust in and out of your soaking pussy, your moans covering the sound of screams coming from the television 

"God you look so good right now with my cock in you, your face all red and tears dripping down your cheeks.... Only I can make you feel this way" 

His continued to thrust in you hard his cock filling you up

"Shit... I wanted this for so long and I finally got it.... i got you,  
And im never letting go.and i know you wanted this too i hear you at night when you touch yourself while moanin my name"

"You h-heard me?" 

You moaned out 

"Damn right i did.It always got me so worked up... Now im finally doin something about it"

You felt a knot building up in your stomach 

"Sans! Im gonna-" you breathed out 

"You gonna cum?go ahead... Cum for me..."

And you did, hard. All over sans's dick causing him to orgasm all inside you filling you up with his blue magic that spilled out of you when he pulled put

You were panting and sans laid on top of you holding you close 

"That was....fantastic" 

"Yeah it was,...what do ya say i go run us a bath, we go up to my room and do this again?"

You smiled 

"That sounds like a great idea"

**Notes for the Chapter:**

> Tell me how i did, this is my first fan fic so I appreciate constructive criticism  
> (Also looking for co writers)  
> And im still taking request !!!


	3. Bara underfell sans x reader 🍋

in the underground, everyone knew sans, and everyone knew not to mess with him, from a outsiders point of view sans was a cold blooded murderer that killed any one that stood in his way

Thats why everyone was surprised when you, a human fell underground  
And sans protected you  
You almost died out in the cold in nothing but shorts and a tank top ,but sans gently carried you to his home and gave you a bed to sleep in

You weren't scared of sans, not even a little and that's what sans loved about you, you didnt treat him like a big scary monster you treated him like a person

you've been living with sans with for about 2 months, you and sans a established romantic relationship but have yet to kiss or do anything else of the sort, tonight you were asleep in your bed when you had a nightmare, a nightmare about your past , a nightmare you wish you could forget, you grab your blanket and knock on sans's door gently 

"That you doll?"

"Yeah....can I..come in? I had a bad dream.."

There was a moment of silence before sans spoke "sure sweetheart come on in..." You opened the door, sans lamp was on and he was leaning up in bed 

"You wanna sleep next to me tonight doll?"

You nodded slowly 

He pat next to him and you climbed into bed with him 

"You wanna talk about your nightmare?"

You shook your head , and leaned into sans's arms, face against his chest, you couldn't see it but his face was completely red 

"No...i just wanna be here ...with you"

"Well im here for ya doll, I got you..."

"Sans...?"

"Yeah sweetheart?"

"Can you promise you won't ever leave me"

Sans pulled away from the hug to look you in the eyes and he put a boney hand on your cheek

"Of course id never leave, im nothing without you doll"

You looked in sans's red pinpricks and you felt tears swell in your eyes 

"Shit...doll Don't cry"

Sans tried to comfort you by petting your hair as he held you, eventually it calmed you down and you began to drift into sleep

When you woke up sans wasn't in bed you looked around the room and didnt see him at all, 

You started to panic and began hyperventilating

You heard the door open and a loud crashing sound, you looked up and to see a concerned sans and what seemed to be a tray of breakfast on the floor 

Sans rushed toward you "You okay doll!? What happened?

You sniffled "I saw you were gone.....i got scared" 

"Its okay sweetheart im right here, i gotcha" you took deep breaths as you calmed down

"Im sorry i made you drop breakfast..."

"Its okay doll, why don't we go down stairs and make some more, i'll clean this up after" 

You nodded and sans wrapped your arms around sans as he picked you up and carries you down stairs to make breakfast 

After breakfast you and sans decided to watch some tv, sans sat on the couch and you had sat on his lap 

The movie you were watching was oddly sexual and you were wondering why alphys ever suggested it

You looked at sans face which seemed to be as red as yours 

On the screen was a scene of a human girl pleasuring herself

It didnt show anything really besides her face but it was still enough to make you blush you moved around uncomfortably completely forgetting that your sitting on sans's lap 

"I wouldn't move to much if I where you kid"

Sans said voice low, it send shivers down your spine and you tried to stay completely still 

You weren't paying attention to the movie anymore all you could think about was how much you wanted sans to touch you

You decided to try something

You slightly wiggled your ass on sans's lap and sans grunted

"I'm warning ya doll, if you keep doin that your gonna be in for a bad time.." He growled

You've never heard him like this before, you liked it

You did one last wiggle and sans snapped , a arm wrapped around you forcing you to his chest, his magic spread your legs open wide as sans shoved a hand inside your shorts feeling your wet lips

" I tried to warn you doll" he started to rub his finger against your clit, and you moaned 

"But you just dont listen to you?"

He shoved 2 fingers inside you 

"Fuck...sans"

"My name isnt sans right now doll face, its daddy"

You whined 

"Daddy.. Please , more"

"What's that doll? Be a big girl and use your words"

"Please just fuck me daddy"

Sans stuck another finger in 

"Isnt that what im doin doll?"

"I mean.....w-with your cock!" you moaned out 

"What's the magic word princess?"

"Please!!!" You gasped 

Sans chuckled 

"Any thing for you sweetheart" 

He pulled out his erect red dick and rubbed it a few times, he used his fiery magic to turn you to face him, your pussy felt exposed and you looked down to see your shorts and panties were gone, you blushed and sans gently lowered you on his cock until all 9 inches filled you up

Sans started to thrust up bouncing you up and down on his cock slowly, it felt amazing but you soon wanted more and you started moving up and down yourself, fast and hard 

"Shit doll......never knew you liked it so rough" he grinned and held your hips as his dick thrust in and out of you 

"Fuck you look so good like this sweetheart .... Ridin my cock like a good girl"

Sans Leaned over and started licking your neck and softly biting , then his hands went up your sides and to your breast and he started playing with your nipples causing you to let out a moan 

Soon you felt a knot start to form in your stomach 

"Ah~ daddy, I think I gonna ...im gonna cum" you said breathlessly 

"I'm close too doll..go ahead and cum for me sweetheart"

After a few more thrust you felt the knot snap and you orgasmed ,you basically screamed sans name , clinging onto him, he soon had a orgasm too and came inside you filling you with red seed 

You flopped down on sans's chest, dick still inside you and sans let out a small chuckle 

"That was pretty good for round one doll"

**Notes for the Chapter:**

> Tell me how i did  
> Edit: i tried to fix some spelling errors, I have dyslexia so spelling will not be great


	4. Grillby x reader 🍋

Monsters had been free from the underground for almost 3 years 

Everyone was afraid at first

Terrified the monsters would try and kill us

Like in the stories

But when people saw they weren't a threat and didn't want to hurt anyone 

they let the monsters stay

It took a while to get used to But now monsters and humans live in harmony 

For the most part, some people are extremely racist against monsters . Like your dad...

But you didn't let his racism effect your view of monsters!

You had even moved in with one

His name was grillby , he was a flame monster who owned a popular restaurant named after him 

You where a artist...

You got along pretty well even if he didn't really say much and you only ever saw him early in the morning and night

But still you had a unspoken bond 

On weekend's you and grillby eat dinner together Listen to music and sometimes drink a little wine, This was one of those nights 

You and grillby were in the kitchen, you had already drunk 2 glasses of wine 

Grillby had 4 

You sat On top of the counter 

You were feeling pretty buzzed 

You were looking at grillby , who's mind seemed to be elsewhere as he stared of into the distance at nothing

Grillby was wearing a white buttoned shirt, with the sleeves rolled up 

You couldn't help but stare at his arms 

They where surprisingly muscular for a being made out of fire 

, eventually grillby noticed you staring at him

But your eyes where still fixed on his muscular arms

"Got something on your mind?"

He said, almost smugly 

You snapped out of your daze and looked at grillby , smiling

Pherhaps it was the alcohol but you thought grillby looked really good right now...

"Has anyone ever told you that you're hot?"

You laughed, it was a pun but it wasn't a joke  
You meant it 

Grillby blushed a light blue

Cute , you thought

You didnt know he could blush 

Grillby laughed nervously at the joke

Rubbing his neck

Suddenly a song came on

It was the song that was playing at grillbys when you first met 

Grillby had offered you his hand to shake and you looked at him terrified 

Like he was going to burn you 

He had just chuckled and told you his flames wouldn't hurt you

You laughed too, shaking his hand.

Grillby seemed to have noticed the song too

He extended his hand to you

"Would you like to dance? I promise i won't burn you" 

You giggled and took his had hopping of the counter 

You danced while you both held onto each others hands 

You weren't to close but you weren't far apart

The dance wasn't really serious

You both laughed and giggled 

And grillby gave you a twirl 

And then dipped you down

You both stared at each othe for a moment 

Arms around his neck 

You both slowly leaned in

and you kissed 

Both of you where blushing 

Grillby put a hand to your cheek it felt warm and fuzzy 

Another hand still dipping you

The kiss started to get heated,( pun intended)

he brought you back up 

You both knew where this was going 

You continued to kiss as grillby lifted you up. And you wrapped your legs around his waist 

You moaned as something warmed slipped into your mouth 'What you can only assume was his tongue

Grillby set you on top of the counter, your legs still wrapped around him 

You were wearing a dress, with no panties

Grillby had a hand on your thigh 

He pulled away from the kiss

"Is it alright if I...."

He moved his hand up along your leg closer to your dripping heat 

You nodded " please..."

You could see a smile as he slipped a finger in your wet folds 

He traced your clit

Slowly

It was agonizing

You were going to start begging him to do more when he shoved 2 hot fingers in you 

You moaned out 

"Nnngg.... Grillby...."

You could hear a low chuckle and his fingers pumped in and out of you 

God you've never been so turned on in your life 

"Grillby...please.. I need you"

Grillby wasnt one to deny a lover

He unbuckled his hands and belt, pulling out a thick fiery cock that looked to be 8 inches 

But it was still scary, 

"W-wait" you said 

"What is it? Would you like me to stop?"

Grillby asked , worried 

"No no! I just...... This is kinda my first time"

Grillby seemed surprised

"Oh I see......you would like me to be gentle?"

You nodded 

"Okay... But it might sting at first.."

Grillby grabbed you hand softly 

Before slowly pushing into you

It stung so much... You winced in pain 

"Wait- I need a moment to adjust..." You said

"Alright, tell me when you are ready" grillby said, softly 

You waited a few moments until the pain subsided 

You moved your hips to see if it was alright and you let out a little moan at the sensation 

"Okay you can go now..."

Grillby began to thrust inside you, slowly

Taking his time 

You felt so good

Like a warmness was filling you 

It was amazing 

"Grillby! Please...go harder"

Grillby started to thrust harder

And groaned 

"Oh my... You are.." He grunted "really tight"

You couldn't respond 

You were too busy lost in your own pleasure with his cock deep inside you

"Fuck... Grillby this feels amazing"

Grillby gripped onto your thighs as he pounded into you 

"I never thought I'd get to see you like this... Moaning on my cock, you look amazing..." he growled 

You let out a whimper

You've never heard grillby talk like that

Grillbys flames seemed to be hotter than ever not burning you but definitely heating you up

Soon you felt it

You where about to cum 

"Grillby- I'm so close..." You breathed out 

Grillby grunted " me too love ......"

Love? Grillbys never called you that...it made your cheeks warm 

Soon you felt grillbys hot flaming magic fill you up 

It was so hot and felt so good , so so good

You felt a orgasm rush over you, your juices mixed with grillbys magic 

Grillby pulls you in for a tender kiss as you both rode your orgasm

When you both calmed down and grillby pulled out of you 

"I guess this as good as time of any to confess something to you..."

Grillby spoke

You tilted your head 

"You see ... I have had feelings for you... For some time now, I was afraid you were going to reject me . but I must tell you now..... Do you.... Feel the same way ?"

He asked 

You smiled

"Yes I feel the same way! And... I'd really like to be with you.. I mean we already live together and everything "

Grillby gave you a kiss

"Im so glad you feel the same"

You both hugged each other closely

"Now... Take of your dress"


End file.
